I know the value but can you please show me the graph and how did you get the value from the graph?

Thank you

is 30, as you clearly know. If you are familiar with the graph of , then you can draw this and the line that you draw from 0.5 on the x-axis will meet at 30 degrees on the y-axis.
The graph can be shown here:http://www.quickmath.com/www02/image...t/example4.gif
On the graph, take 3 as the value of 180 and hence 1 as 60. You can see that if you drew a line from 0.5, it would meet halfway to 1 - which is 30!